Machine for bending, folding, pressing, or shearing of plates and the like



March 23, 1954 L. ARTMANN 2,672,912

MACHINE FOR BENDING, FOLDING, PRESSING, OR SHEARING OF PLATES AND THE LIKE Filed July 9, 1949 J72 ven Z07 .5 5161 3012 firZman/z Patented Mar. 23, 1954 ED STATES PATENT OFFICE MACHINE FOR BENDING, FOLDING, PRESS- G 0F PLATES AND THE ING, OR SHEARIN LIKE Ludwig Artmann, Hamburg, Germany Application July 9, 1949, Serial No. 103,794

4 Claims.

My invention relates to improvements in machines with which sheet metal or plates are bent, folded or pressed by hydraulic, pneumatic or mechanical power means, and more particularly to such machines made of structural sections and plate steel; HeretOfore such machines or presses have occasionally been made out of structural material by some shops for their own use but they had'the disadvantage of not being precise and being unsuitable for heavy work and high pressures.

An object of my invention is to provide such a press suitable for mass-production, simple in construction and having surprisingly light weight for its capacity. 7

V Another-object of my invention is to provide means overcoming the shortcomings caused by deflection of the bending beams in such machines, which shortcomings include inaccurate bends and folds especially in hard material requiring high pressures.

Still another object of my invention is to provide simple adjusting means for the stroke of the pressure rams without causing undue bending and shearing stresses on by locating cylinders and rams for operation of the bending beams substantially within the plane of the side uprights. v I

Other objects of the invention reside in some details of construction, an inventive combination of parts and other features as will hereafter be fully described and pointed out, reference being had to the accompanying drawings in which like parts are designated by like characters and in which:

Fig. 1 is a front view of the press with side uprights partly sectioned to show more details.

Fig. 2 isa vertical section through thepress taken along the line 2--2 of Fig- 1.

Fig. 3 shows bending beams, shaped according to my invention, under pressure. 7

' Referring now particularly to Fig. 1 of the drawings, the reference characters la and lb represent the two uprights of the press, preferably made of structural sections or plate steel. Furthermore, 2 is the stationary upper and 3 the reciprocable lower bending beam. The drawings show only presses with reciprocation imparting means at the bottom, but my invention may as well be applied to presses operated from the top, in which case the moving bending beam would be the upper one and the lower would be stationary. The bending beams are inserted into apertures 5 and 6 in the side uprights into which the strip-shaped bending or folding tools 2a and 3a construction parts O also extend. The upper closed with cover plates 4 after the upper bending beam 2 has been inserted and fastened. Between the lower part of apertures 5 and. apertures 6 projections l are left which serve as upper stops for bending beam 3, coacting with lugs 3b on top of the lower flange of said bending beam. The press, as shown by way of example in the drawing, is operated by hydraulic rams 8 with cylinders 9. Each end of bending beam 3 is provided with apertures lll substantially within the plane of apertures 6, forming in conjunction therewith, crosswise apertures. Into these apertures on top of lug 3b, shims ll may be placed whereby the stroke of bending beam 3 may be adiusted in a very simple and effective manner. Shims may also be insertedbetween rams 8 and. bending beam 3, thereby slanting the beam somewhat. This arrangement may be useful for producing bends or folds at one side of a plate blending into the flat surface at a distance from the edge. The downward stroke of the bending beam 3 is adjustablylimited by two jackscrews I2 10- catedbetween the two side uprights. Instead of shims ll, as shown in the drawing for example, other means of adjustment for the upper limitation of the stroke, such as wedges, jackscrews or others, are conceivable and may be arranged between lower flanges of bending beam 3 at lugs 3b and the projections l.

Experience has shown that both bending beams tend to deflect more or less in operation when some load is applied or pressure exerted on them.

parts of apertures 5 are Thereby some play is caused at the center, preventing accurate bending or folding operations at this point. The. aim of my present invention is to prevent the occurrence of this play by giving the working faces of the bending beams 2 and. 3 such a shape that they become plane and parallel to each other under pressure. This result may be achieved in a makeshift manner by putting shims between bending beams and the at-' tached strip-shaped working tools 2a and 3alat thecenter making the thickness of said shims correspond to the occurring deflection under pressure. Another means would be to stress the bending beams advance in such a manner that under pressure they would attain a straight working face. The first named possibility is only makeshift, and the second causes considerable difficulty as it is practically impossible to prestress a bending beam in the manner required.

According to my invention, I have solved the problem of preventing play by loading the bending beams 2 and 3 before assembling the same into the press in such a manner that they deflect the same as later on under pressure. After removing the load, the bending beams return to their former shape as shown in Fig. 1, having now a convex working face bulging outwardly at the center. It is also possible to approximate the working faces thus obtained by planning the bending beams from both ends at an angle toward the center and substantially in the direction of the deflection parabola without noticeable sacrifice in the final result. The little clearance now encountered between the thusly prepared working faces and the straight strip-shaped working tools 2a and 3a could be avoided by correspondingly shaping the tools, but practically this clearance can be neglected as it is very small not amounting to much more than some hundredths of an inch by bending beam lengths of ten and more feet. Defiections in this range may appear negligible but they sufiice to render precise bending and folding operations with a press, not modified by the improvements of my invention, impossible. Bending beams prepared according to my invention and subjected to load and pressure in operation will deflect in such a way, that both working faces are flat and parallel to each other, as shown in Fig. 3, thereby assuring also straight tool edges giving perfect bends and folds in the material to be operated on, even if the material is of high strength and great hardness. It is to be understood that the described process is not limited to the bending beams, but that also the working tools for bending and folding 2a, 3a, may be finished accordingly so that their working edges get straight and parallel under pressure.

It is obvious that the novel method of my invention is a very simple and ingenious solution of the problem involved. All stresses to which the press is subjected in operation are taken up by the side uprights la and lb for which reason ordinary structural beams may be used as bending beams instead of riveted or welded plate constructions otherwise necessary to minimize deflection. Considerable reduction in manufacturing cost is thereby realized without sacrifice in performance.

Having thus described a preferred form of my invention, I do not wish to be limited thereto, but desire the appended claims to be construed as broadly as permissible in view of the prior art.

What I claim is:

1. In a machine for bending, pressing, and shearing of sheet material and the like, an upper stationary press beam, a lower press beam, an upright at each end of said press beams, apertures in said uprights for the end portions of said lower press beam, means for moving said lower press beam upwards in said apertures,

apertures in relation to the upper edge thereof, and means projecting laterally into said upright apertures for engagement with the upper surface of said varying means to limit the upward movement of said lower press beam.

2. In a machine for bending, pressing, and shearing of sheet material and the like, an upper stationary press beam, a lower press beam, an upright at each end of said press beams, apertures in said uprights for the end portions of said lower press beam, hydraulic means for moving said lower press beam upwards in said apertures, means for limiting the downward movement of said lower press beam, apertures in said lower press beam adjacent said uprights, means for varying the level of the lower edge of said beam apertures in relation to the upper edge thereof, and means projecting laterally into said upright apertures for engagement with the upper surface of said varying means to limit the upward movement of said lower press beam.

3. In a machine for bending, pressing, and shearing of sheet material and the like, an upper stationary press beam, a lower press beam, an upright at each end of said press beams, apertures in said uprights for the end portions of said lower press beam, hydraulically actuated plungers in said upright apertures in engagement with the bottom surface of said lower press beam for moving said lower press beam upwards in said apertures, means for limiting the downward movement of said lower press beam, apertures in said lower press beam adjacent said uprights, means for varying the level of the lower edge of said beam apertures in relation to the upper edge thereof, and means projecting laterally into said upright apertures for engagement with the upper surface of said varying means to limit the upward movement of said lower press beam.

an inclined position.

means for limiting the downward movement of said lower press beam, apertures in said lower press beam adjacent said uprights, means for varying the level of the lower edge of said beam LUDWIG ARTMANN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 535,207 Jones Mar. 5, 1895 532,457 Hammond Jan. 15, 1895 610,585 Guild Sept. 13, 1898 629,532 Thomas July 25, 1899 1,154,918 Goldschmidt et al. Sept. 28, 1915 2,133,477 Schade Oct. 18, 1938 2,385,247 Yeomans Sept. 18, 1945 2,522,745 Byerlein Sept. 19, 1950 FOREIGN PATENTS Number Country Date 544,605 Germany Feb. 19, 1932 431,457 Great Britain July 8, 1935 

